The present invention relates to liquid crystal displays including backlights for illuminating the displays.
Liquid crystal displays (LCDs) are used in a variety of applications, including portable computers, flat screen televisions and vehicle, ship and aircraft instrumentation. Most LCDs require an illumination source, or backlight unit, for backlighting the LCD so that the image displayed on the LCD can be seen by a viewer. For example, backlight units are described in U.S. Pat. Nos. 5,645,337 and 4,487,481, the disclosures of which are hereby incorporated herein by reference.
In designing such a backlight unit, the designer has to consider a number of design parameters. For example, the rated life of the backlight unit is an important consideration since frequent replacement of the backlight unit, or the light source therein, is costly and time consuming. The brightness of the display must be at a certain level in order for a viewer to see the image. Further, design concerns include the amount of time it takes for the backlight unit to begin operation after being turned on, the operating temperature of the backlight unit, the power consumption of the backlight unit, the stability of the brightness of the backlight unit over a temperature range and the amount of electromagnetic interference generated by the backlight unit.
The present invention may address one or more of the matters set forth above.
Certain aspects commensurate in scope with the originally claimed invention are set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of certain forms the invention might take and that these aspects are not intended to limit the scope of the invention. Indeed, the invention may encompass a variety of aspects not be set forth below and may encompass different combinations of the aspects set forth below.
In accordance with one aspect of the invention, there is provided a display device which includes an electrodless light source, or lamp and a display unit. The display unit comprises a LCD element for displaying an image using, in part, light generated by the lamp. A diffuser may be interposed between the lamp and the LCD element for uniformly illuminating the LCD element.
In accordance with another aspect of the invention, a backlight unit is comprised of a light guide which receives light from one or more lamps through one or more of its ends.
These and other features and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings and the appended claims.